Construction

Motorcycle construction

Motorcycle construction is the engineering, manufacturing, and assembly of components and systems for a motorcycle which results in performance, cost and aesthetics desired by the designer. With some exceptions, construction of modern mass-produced motorcycles has standardised on a steel or aluminium frame, telescopic forks holding the front wheel, and disc brakes. Some other body parts, designed for either aesthetic or performance reasons may be added. A petrol powered engine typically consisting of between one and four cylinders (and less commonly, up to eight cylinders) coupled to a manual five- or six-speed sequential transmission drives the swingarm-mounted rear wheel by a chain, driveshaft or belt.

Fuel economy

Motorcycle fuel economy benefits from the relatively small mass of the vehicle. This, of course, relates to how the motorcycle is used. One person on a small motorcycle travelling a short distance is generally very economical. However a large motorcycle generally has bad aerodynamics compared with a typical car, poor aerodynamics of exposed passengers and engines designed for goals other than fuel economy can work to reduce these benefits. Riding style has a large effect on fuel economy.

Fuel economy varies greatly with engine displacement and riding style ranging from a low of 29 mpg_-US (8.1 L/100 km; 35 mpg_-imp) reported by a Honda VTR1000F rider, to 107 mpg_-US-imp) reported for the Verucci Nitro 50 cc Scooter. A specially designed Matzu Matsuzawa Honda XL125 achieved 470 mpg_-US (0.50 L/100 km; 560 mpg_-imp) "on real highways - in real conditions."

Due to lower engine displacements (100 cc–200 cc), motorcycles in developing countries offer good fuel economy. In the Indian market, the second most selling company, Bajaj, offers two models with superior fuel economy: XCD 125 and Platina. Both are 125 cc motorbikes with a company-claimed fuel economy of 109 km/l and 111 km/l, respectively.

Electric motorcycles

Very high fuel economy equivalents can be derived by electric motorcycles. Electric motorcycles are nearly silent, zero-emission electric motor-driven vehicles. Operating range and top speed suffer because of limitations of battery technology. Fuel cells and petroleum-electric hybrids are also under development to extend the range and improve performance of the electric motors.

Windscreen

Also called windshields or screens, windscreens can be built into a fairing or be attached to an otherwise unfaired bike. They are usually made from transparent high-impact acrylic plastic. They may be shaped specifically to direct air flow over or around the head of the rider even if they are much shorter than the seated rider. Some motorcycles have electric screens, introduced on the 1986 BMW K100LT, which raise and lower the screen with the push of a button to the optimum height for conditions.
In the absence of a fairing or screen, a phenomenon known as the windsock effect occurs at speeds above 100 km/h (62 mph), where the rider becomes a major source of drag and is pushed back from the handlebars, tiring the rider.However, these motorcycles still effectively push their way through the atmosphere with brute force. A cabin cycle, which has a hull that wraps around the basic cycle frame, solved the problem of aerodynamics by isolating driver from outside air.